[PATCH v10 04/10] powerpc/kprobes: Mark newly allocated probes as ROX
From: Jordan Niethe <hidden>
Date: 2021-03-30 04:53:56
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
From: Russell Currey <redacted>
Add the arch specific insn page allocator for powerpc. This allocates
ROX pages if STRICT_KERNEL_RWX is enabled. These pages are only written
to with patch_instruction() which is able to write RO pages.
Reviewed-by: Daniel Axtens <redacted>
Signed-off-by: Russell Currey <redacted>
Signed-off-by: Christophe Leroy <redacted>
[jpn: Reword commit message, switch to __vmalloc_node_range()]
Signed-off-by: Jordan Niethe <redacted>
---
v9: - vmalloc_exec() no longer exists
- Set the page to RW before freeing it
v10: - use __vmalloc_node_range()
---
arch/powerpc/kernel/kprobes.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c
index 01ab2163659e..3ae27af9b094 100644
--- a/arch/powerpc/kernel/kprobes.c
+++ b/arch/powerpc/kernel/kprobes.c@@ -25,6 +25,7 @@ #include <asm/sections.h> #include <asm/inst.h> #include <linux/uaccess.h> +#include <linux/vmalloc.h> DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL; DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
@@ -103,6 +104,19 @@ kprobe_opcode_t *kprobe_lookup_name(const char *name, unsigned int offset) return addr; } +void *alloc_insn_page(void) +{ + if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)) { + return __vmalloc_node_range(PAGE_SIZE, 1, MODULES_VADDR, MODULES_END, + GFP_KERNEL, PAGE_KERNEL_ROX, VM_FLUSH_RESET_PERMS, + NUMA_NO_NODE, __builtin_return_address(0)); + } else { + return __vmalloc_node_range(PAGE_SIZE, 1, MODULES_VADDR, MODULES_END, + GFP_KERNEL, PAGE_KERNEL_EXEC, VM_FLUSH_RESET_PERMS, + NUMA_NO_NODE, __builtin_return_address(0)); + } +} + int arch_prepare_kprobe(struct kprobe *p) { int ret = 0;
--
2.25.1